`cos^(-1) (1/sqrt2 (cos ((7pi)/5)-sin((2pi)/5)))` is equal to `(a pi)/b` where `a,b in N` and `a` is prime then `(b-2a)=`

if cos^(-1)((1)/(sqrt(2))(cos((7pi)/(5)-sin((2pi)/(5)))=(ppi)/(q) (where p,q are in lowest form), then value of (q-p) is

cos^(-1){(1)/(sqrt(2))(cos(7 pi)/(5)+sin(2 pi)/(5))} is equal to (A) (23 pi)/(20) (B) (13 pi)/(20) (C) (3 pi)/(20) (D) (7 pi)/(20)

If x=2cos theta-3sin theta & y=2sin theta+3cos theta such that (dy)/(dx) at theta=(pi)/(4) is equal to (a)/(b) (where a & b are relatively prime),then |a+b| is equal to

cos^(-1)((cos(7 pi))/(6)) is equal to ( a ) (7 pi)/(6) (B) (5 pi)/(6) (C) (pi)/(3)(D)(pi)/(6)

The value of sin^(-1)(cos(cos^(-1)(cos x)+sin^(-1)(sin x))) where x in((pi)/(2),pi), is equal to (pi)/(2)(b)-pi(c)pi (d) -(pi)/(2)

The value of cos^(-1)(cos(5pi)/3)+sin^(-1)(sin(5pi)/3) is pi/2 (b) (5pi)/3 (c) (10pi)/3 (d) 0

(1+cos.(pi)/(8))(1+cos.(3pi)/(8))(1+cos.(5pi)/(8))(1+cos.(7pi)/(8)) is equal to

(cos pi) / (5) + (cos (2 pi)) / (5) + (cos (6 pi)) / (5) + (cos (7 pi)) / (5) = 0